【摘要】 以分离自海洋沉积物中异化铁还原细菌Klebsiella sp. KB52为研究对象,分析微生物异化铁还原过程对还原Cr（Ⅵ）的影响。菌株KB52是一株非典型耐铬细菌,在Cr（Ⅵ）浓度10～50 mg·L^-1范围内,该菌株生长受到明显抑制。当将Fe（OH）³添加至培养体系,菌株KB52能够良好生长并具有铁还原性质,同时提高了Cr（Ⅵ）还原效率。Fe（OH）³浓度为300 mg·L^-1时,菌株KB52细胞生长指标OD600和累积产生Fe（Ⅱ）浓度最高,分别是1.4760±0.04和（39.79±1.45）mg·L^-1,Cr（Ⅵ）还原率（42%）是对照组的5.25倍。当柠檬酸铁作为电子受体,菌株KB52还原Fe（Ⅲ）效率最高,Fe（Ⅱ）累积浓度达到（109.87±1.27）mg·L^-1,Cr（Ⅵ）还原率提高至67%。上述结果表明,菌株KB52能够利用可溶性和不可溶性Fe（Ⅲ）作为电子受体进行生长,同时其异化铁还原过程偶联Cr（Ⅵ）还原。研究结果可为利用异化铁还原细菌还原Cr（Ⅵ）提供理论依据,拓宽微生物治理重金属污染的应用范围。更多还原

【Abstract】 Fe（Ⅲ）-reducing bacterium Klebsiella sp. KB52 isolated from marine sediment was used to investigate the effect of microbial Fe（Ⅲ） reduction on Cr（Ⅵ） reduction. Strain KB52 was not a typical chromium-tolerant bacterium, its cell growth was obviously inhibited over a range of Cr（Ⅵ） concentration from 10 to 50 mg·L^-1. As Fe（OH）³ was added into the culture system as an electron acceptor, a good cell growth for strain KB52 occurred with Fe（Ⅲ） reduction ability, which led to the increase of Cr（Ⅵ） reduction rate. The results showed that the absorbance values（OD600） and Fe（Ⅱ） concentration reached their maximum value of 1.476 0 ± 0.04 and（39.79 ±1.45） mg·L^-1, respectively, and the Cr（Ⅵ） reduction rate（42%） was 5.25 times of the control group at the Fe（Ⅲ）concentration of 300 mg·L^-1. When ferric citrate was used as an electron acceptor, strain KB52 showed the highest Fe（Ⅲ）-reducing activity, and the Fe（Ⅱ） accumulation content could reach（109.87 ± 1.27） mg·L^-1, Cr（Ⅵ）reduction rate increased up to 67%. The results showed that Fe（Ⅲ）-reducing bacterium KB52 could use both soluble and insoluble Fe（Ⅲ） as electron acceptor, and promote its cell growth, Fe（Ⅲ） reduction and Cr（Ⅵ）coupling reduction. The results demonstrated that Cr（Ⅵ） reduction by Fe（Ⅲ）-reducing bacterium is an effective method, which could provide evidence for the application of microorganism to treating heavy metal pollution.更多还原